Reduced FDG dose levels for PET/MRI show mixed results

April 6, 2017

Even though a lower dose of FDG had no significantly adverse effect on lesion detection for most adult cancer patients undergoing a whole-body PET/MRI scan, German researchers recommend that clinicians stay with recommended levels to avoid artifacts, according to a study published online March 30 in TheJournal of Nuclear Medicine.

The researchers found that FDG dose could go as low as 2 MBq/kg based on body weight (BW) with no significant degradation in diagnostic image quality in most middle body areas. However, FDG doses below the standard level of 3 MBq/kgBW also resulted in large artifacts in the abdominal/pelvic region (JNM, March 30, 2017).

"The occurrence of this artifact cannot currently be predicted and the clinical impact is unclear," wrote lead author Dr. Ferdinand Seith from Eberhard Karls University Tübingen and colleagues. "Therefore, we do not recommend reducing doses below 3 MBq/kgBW in oncologic PET/MRI examinations in adults at this time."